Spring Reactive Sample

Note

A huge thanks to @rajadilipkolli for his efforts in updating this repository to the newest Spring Boot v4.

This is a sandbox project for demonstrating Reactive Streams support in the Spring framework and the broader Spring ecosystem.

I've also maintained a series of repositories related to Reactive Streams and the latest Spring 5:

• Spring RSocket Sample
• Spring Kotlin Coroutines Example
• Spring Kotlin DSL/Spring Fu Sample
• Spring WebMvc Functional Example
• Angular and Spring Reactive Example
• Spring R2dbc Example (updates for Spring 5.3, Spring Data R2dbc 1.2, and Spring Boot 2.4)

The source codes have been updated to Spring 7 / Spring Boot v4.

• The Spring Boot 3.x based codes are available in a compressed archive and tagged with boot-3.
• The Spring Boot 2.x based codes are available in a compressed archive and tagged with v1.0.

Documentation

Read online: https://hantsy.github.io/spring-reactive-sample/

Sample Codes

The following table lists all sample codes available in this repository.

Spring Samples

Name	Description
vanilla	Basic spring-webflux features with a main class to start the application
vanilla-reactor-netty2	Same as vanilla, but uses Reactor Netty 2.x as the runtime
vanilla-jetty	Same as vanilla, but uses Jetty as the runtime
vanilla-tomcat	Same as vanilla, but uses Tomcat as the runtime
vanilla-undertow	Same as vanilla, but uses Undertow as the runtime
java8	Java 8 CompletableFuture and @Async example
java9	Same as vanilla, with Java 9 Flow API support (see SPR-16052)
rxjava3	Same as vanilla, but uses RxJava 3 instead of Reactor (since Spring 5.3.0)
smallrye-mutiny	Same as vanilla, but uses SmallRye Mutiny instead of Reactor (since Spring 5.3.10)
rxjava3	Same as vanilla, but use Rxjava3 instead of Reactor, since Spring 5.3.0
smallrye-mutiny	Same as vanilla, but use SmallRye Mutiny instead of Reactor, since Spring 5.3.10
war	Replaces the manual bootstrap with Spring ApplicationInitializer, can be packaged as a war file for external servlet containers
routes	Uses RouterFunction instead of @Controller
register-bean	Programmatic bean registration in ApplicationContext at bootstrap
data-elasticsearch	Spring Data ElasticSearch Reactive example
data-neo4j	Spring Data Neo4j reactive example
data-mongo	Spring Data Mongo Reactive example
data-mongo-pageable	Spring Data Mongo Reactive example with pagination support
data-mongo-transaction	Spring Data Mongo Reactive example with Transaction support
data-redis	Spring Data Redis Reactive example
data-redis-message	Spring Data Redis Reactive example with ReactiveRedisMessageListenerContainer
data-cassandra	Spring Data Cassandra Reactive example
data-couchbase	Spring Data Couchbase Reactive example
security	Adds Spring Security Reactive support to vanilla
security-form	Same as security, with login form example
security-user-properties	Same as security, but stores users in users.properties
security-method	Replaces URI-based configuration with method-level constraints
security-data-mongo	Based on data-mongo and security, replaces hard-coded users with Mongo-driven store
multipart	Multipart request handling and file uploading
multipart-data-mongo	Multipart and file uploading, data stored in Mongo via Spring Data Mongo Reactive GridFsTemplate
mvc-thymeleaf	Traditional web application using Thymeleaf as template engine
mvc-mustache	Traditional web application using Mustache as template engine
mvc-freemarker	Traditional web application using Freemarker as template engine
sse	Server Send Event example
websocket	WebSocket example
websocket-reactor-netty2	WebSocket example with Reactor Netty 2
web-filter	WebFilter example
groovy	Written in Groovy
groovy-dsl	Groovy DSL bean definition example
client	WebClient example for calling backend reactive APIs
client-jetty	WebClient with Jetty Reactive HttpClient
client-reactor-netty2	WebClient with Reactor Netty 2.x HttpClient
client-jdk11-httpclient	WebClient with JDK 11 HttpClient
client-apache-httpclient5	WebClient with Apache HttpClient 5
cache	Cache Async/Reactive support with in-memory ConcurrentHashMap
cache-caffeine	Cache Async/Reactive support with Caffeine
cache-redis	Cache Async/Reactive support with Redis
event	Application Event Reactive example
kotlin	Written in Kotlin
kotlin-co	Written in Kotlin Coroutines
kotlin-routes	Kotlin functional approach to declare beans and bootstrap programmatically
kotlin-dsl	Kotlin DSL bean definition example
schedule	Spring Schedule Reactive example
session	Spring Session example
session-header	Spring Session WebSessionIdResolver example
session-data-redis	Spring Data Redis based ReactiveSessionRepository example
session-data-mongo	Spring Data Mongo based ReactiveSessionRepository example
exception-handler	Exception Handler example
integration	Spring Integration example
integration-dsl	Spring Integration Java 8 DSL example
restdocs	Spring RestDocs example

Spring Boot Samples

Name	Description
boot-start	Spring Boot example with 3 Maven profiles to switch between Jetty, Tomcat, and Undertow
boot-start-routes	Simple RouterFunction example
boot-mvc-thymeleaf	Same as mvc-thymeleaf, based on Spring Boot
boot-mvc-mustache	Same as mvc-mustache, based on Spring Boot
boot-mvc-freemarker	Same as mvc-freemarker, based on Spring Boot
boot-groovy	Written in Groovy
boot-kotlin	Written in Kotlin
boot-kotlin-co	Written in Kotlin Coroutines
boot-kotlin-dsl	Kotlin-specific BeanDefinitionDSL and RouterFunctionDsl example
boot-kotlin-co-dsl	Kotlin-specific BeanDefinitionDSL and CoRouterFunctionDsl example
boot-redis	Example using ReactiveRedisConnection and RouterFunction
boot-data-redis	Spring Data Redis example
boot-data-neo4j	Spring Data Neo4j example (Spring Boot 2.4)
boot-neo4j	Spring Data Neo4j using ReactiveNeo4jOperations (Spring Boot 2.4)
boot-neo4j-cypher	Spring Data Neo4j using ReactiveNeo4jClient (Spring Boot 2.4)
boot-data-cassandra	Spring Data Cassandra example
boot-data-couchbase	Spring Data Couchbase example
boot-data-elasticsearch	Spring Data ElasticSearch example
boot-data-mongo	Spring Data Mongo example (Repository, Auditing, testcontainers)
boot-data-mongo-querydsl	Spring Data Mongo example with QueryDSL support
boot-data-mongo-gridfs	Spring Data Mongo example with GridFS support
boot-data-mongo-tailable	Spring Data Mongo tailable document example
boot-exception-handler	Global Exception Handler example
boot-pulsar	Spring for Pulsar Reactive example

Legacy Codes

Some example codes are becoming deprecated over time, e.g., the SDN Rx project, which was maintained by the Neo4j team, has been discontinued. It is highly recommended to migrate to the official Spring Data Neo4j.

Spring Data R2dbc 1.2 introduced many breaking changes, so I created another Spring R2dbc Sample repository to introduce the new features.

Spring removed support of RxJava/RxJava2, and other projects, such as Spring Data, will remove RxJava/RxJava2 support soon.

name	description
data-r2dbc	Spring Data R2dbc Example. (Deprecated, go to hantsy/spring-r2dbc-sample to update yourself)
data-r2dbc-postgresql	Spring Data R2dbc Example, but use PostgreSQL instead(Deprecated)
boot-r2dbc	Spring Data R2dbc example using DatabaseClient(Deprecated)
boot-data-r2dbc	Spring Data R2dbc example(Deprecated)
boot-data-r2dbc-auditing	@EnableR2dbcAuditing example(Deprecated)
boot-data-r2dbc-postgresql	Same as boot-data-r2dbc, but use PostgresSQL instead(Deprecated)
boot-data-r2dbc-mysql	Same as boot-data-r2dbc, but use MySQL instead(Deprecated)
boot-data-r2dbc-mssql	Same as boot-data-r2dbc, but use MS SQL instead(Deprecated)
boot-neo4j-rx	SDN Rx Example but use ReactiveNeo4jClient(Deprecated)
boot-neo4j-rx-cypher	SDN Rx Example using Cypher queries(Deprecated)
boot-data-neo4j-rx	SDN Rx Example(Deprecated)
rxjava	Same as vanilla, but use Rxjava instead of Reactor
rxjava-jdbc	Accessing database with rxjava-jdbc. NOTE: rxjava-jdbc is a wrapper of blocking Jdbc APIs
rxjava2	Same as vanilla, but use Rxjava2 instead of Reactor
rxjava2-jdbc	Accessing database with rxjava2-jdbc. NOTE: rxjava2-jdbc is a wrapper of blocking Jdbc APIs

References

• Reactive Streams, official Reactive Streams website

• Understanding Reactive types, Spring.IO

• The WebFlux framework, Spring Framework Reference Documentation

• Reactor Core 3.0 becomes a unified Reactive Foundation on Java 8, Spring.IO

• Reactive Spring, Spring.IO

• Three parts of Notes on Reactive Programming by Dave Syer:

  • Notes on Reactive Programming Part I: The Reactive Landscape
  • Notes on Reactive Programming Part II: Writing Some Code
  • Notes on Reactive Programming Part III: A Simple HTTP Server Application

• Reactive Programming in the Netflix API with RxJava

• Reactor by Example

• New in Spring 5: Functional Web Framework

• Spring WebFlux: First Steps

• Spring-Reactive Example REST Application

• Spring 5 WebFlux and JDBC: To Block or Not to Block

• Reactive Spring 5 and Application Design Impact

• From Java To Kotlin - Your Cheat Sheet For Java To Kotlin

• From Java to Kotlin

• Petclinic: Spring 5 reactive version

• Spring Framework 5 Kotlin APIs, the functional way

• Kotlin extensions for MongoOperations and ReactiveMongoOperations

• Reactive systems using Reactor

• Lite Rx API Hands-On with Reactor Core 3

• reactor-kotlin-workshop

Special Thanks

Special thanks to JetBrains for supporting an open-source license.